Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biochem Genet ; 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38430448

RESUMO

Globally, colorectal cancer (CRC) is one of the leading causes of health problems. More reliable molecular biomarkers for early diagnosis in CRC patients are needed. A crucial role for thyroid hormone receptor interacting protein 6 (TRIP6) is played in tumorigenesis and tumor growth. Our study aims to determine the diagnostic and prognostic roles of TRIP6 at CRC. TRIP6 gene expression levels were analyzed in this study from public databases. The relationship between TRIP6 expression and clinicopathological characteristics was explored by logistic regression analysis. Based on Kaplan-Meier (K-M) survival curves and receiver operating characteristic curves (ROC) analysis, the prognostic and diagnostic values of TRIP6 were determined. Protein-protein interaction (PPI) networks analysis were performed using the STRING database. A Spearman's correlation analysis applied for examining the correlation between TRIP6 expression, immune cell infiltration, and immune checkpoint genes. Moreover, colony formation assay and transwell assay were used to investigate the functions of TRIP6. TRIP6 was highly expressed in CRC cancer tissues and cells. K-M survival analysis indicated that a high expression of TRIP6 was associated with poor prognosis. TRIP6 expression was obviously associated with immune cell infiltration and immune checkpoint gene expression. For validation, the results of collected clinical CRC samples show that TRIP6 levels in CRC tumor tissue were higher than those of paired adjacent colorectal tissues. Additionally, in vitro experiments suggested that TRIP6 knockdown suppressed proliferation and migration in CRC cell line RKO. TRIP6 overexpression promoted the proliferation and migration of normal colon cell line NCM460. High TRIP6 expression is associated with poor prognosis in colorectal cancer and promotes tumor cell proliferation and migration which may be a potential diagnostic and prognostic biomarker and a promising therapeutic target for CRC, providing new insights into its role in CRC.

2.
J Gene Med ; 26(1): e3664, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38282143

RESUMO

BACKGROUND: The primary reason for tumor-related deaths worldwide is lung adenocarcinoma (LUAD). The oncogene IQ motif-containing GTPase activating protein 3 (IQGAP3) is crucial for contributing to tumor initiation and progression. However, the precise function and molecular mechanism of IQGAP3 in LUAD remain unknown. The present study aimed to investigate the expression, prognosis, mechanism and tumor immunity associated with IQGAP3 in LUAD. METHODS: The relationship between IQGAP3 and the poor prognosis of LUAD was analyzed using The Cancer Genome Atlas (TCGA) database. This analysis was further validated on lung cancer tissues and cell lines. The function of IQGAP3 was investigated by silencing it in LUAD cell lines. To predict microRNA (miRNA) and long non-coding RNA associated with IQGAP3, the starBase database was utilized, and the predictions were verified by enhancing the function of miRNA. Finally, the relationship between IQGAP3 and tumor immunity was evaluated using Spearman's correlation analysis. RESULTS: TCGA database revealed that higher levels of IQGAP3 were associated with advanced tumor stage, N stage and poor prognosis in LUAD patients. To confirm that, we conducted experiments on lung cancer tissues and cell lines and found that silencing IQGAP3 significantly inhibited tumor cell proliferation and migration. The expression of IQGAP3 showed a negative correlation with has-miR-101-3p and has-miR-135a-5p, whereas it showed a positive correlation with GSEC, AC005034.3 and TYMSOS. Furthermore, the introduction of miRNA-mimics into lung cancer cell resulted in a significant inhibition of cancer cell growth and migration. Following that, the level of IQGAP3 showed a positive correlation with the infiltration of immune cells in tumors. CONCLUSIONS: These results reveal that IQGAP3 significantly promotes LUAD progression and could serve as a prognostic biomarker for LUAD. Furthermore, IQGAP3 is most likely regulated by the GSEC/TYMSOS-hsa-miR-101-3p axis and the AC005034.3-hsa-miR-135a-5p axis in LUAD.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , MicroRNAs , Humanos , Adenocarcinoma de Pulmão/genética , MicroRNAs/genética , Neoplasias Pulmonares/genética , Linhagem Celular , Proliferação de Células/genética , Transformação Celular Neoplásica , Regulação Neoplásica da Expressão Gênica , Proteínas Ativadoras de GTPase
3.
J Vis Exp ; (185)2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35969074

RESUMO

Gut microbiota dysbiosis is thought to exert a role in the progression of colitis. However, the precise standards for probiotic administration in alleviating colitis remain undefined. Most analysis methods rely on limited diversity and abundance of gut microorganisms. Therefore, observational studies cannot establish causation. In this study, we applied antibiotic-induced pseudo-germ-free mice to investigate the role of gut microbiota in regulating the probiotic effects of Bacillus cereus (B. cereus) on dextran sulfate sodium (DSS)-induced colitis in mice. This process allows for evaluating the bidirectional regulating effect of B. cereus supplementation on health and provides stable and reproducible results. Here, the detailed protocols for B. cereus cultivation, gavage operation, stool collection, and antibiotic clearance treatment on colitis mice are provided. The optimization methods are also applicable for other chronic inflammatory-associated disorders. The results showed that B. cereus administration decreased body weight loss, colon length shortening, disease activity index, and histopathological scores. However, treatment with antibiotics suppressed the positive effect of B. cereus on colitis. These results indicate that gut microbiota are needed for the alleviating effects of B. cereus on colitis. Therefore, exploring the beneficial effects of probiotics in this research is a promising approach for developing novel treatment strategies for alleviating the symptoms of chronic inflammatory-associated disorders.


Assuntos
Colite , Microbioma Gastrointestinal , Animais , Antibacterianos/farmacologia , Bacillus cereus , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colo/patologia , Sulfato de Dextrana , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL
4.
Respir Res ; 22(1): 194, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217280

RESUMO

BACKGROUND: We recently reported histone methyltransferase enhancer of zeste homolog 2 (EZH2) as a key epigenetic regulator that contributes to the dysfunction of innate immune responses to sepsis and subsequent lung injury by mediating the imbalance of macrophage polarization. However, the role of EZH2 in acute respiratory distress syndrome (ARDS)-associated fibrosis remains poorly understood. METHODS: In this study, we investigated the role and mechanisms of EZH2 in pulmonary fibrosis in a murine model of LPS-induced ARDS and in ex-vivo cultured alveolar macrophages (MH-S) and mouse lung epithelial cell line (MLE-12) by using 3-deazaneplanocin A (3-DZNeP) and EZH2 the small interfering (si) RNA. RESULTS: We found that treatment with 3-DZNeP significantly ameliorated the LPS-induced direct lung injury and fibroproliferation by blocking EMT through TGF-ß1/Smad signaling pathway and regulating shift of macrophage phenotypes. In the ex-vivo polarized alveolar macrophages cells, treatment with EZH2 siRNA or 3-DZNeP suppressed the M1 while promoted the M2 macrophage differentiation through modulating the STAT/SOCS signaling pathway and activating PPAR-γ. Moreover, we identified that blockade of EZH2 with 3-DZNeP suppressed the epithelial to mesenchymal transition (EMT) in co-cultured bronchoalveolar lavage fluid (BALF) and mouse lung epithelial cell line through down-regulation of TGF-ß1, TGF-ßR1, Smad2 while up-regulation of Smad7 expression. CONCLUSIONS: These results indicate that EZH2 is involved in the pathological process of ARDS-associated pulmonary fibrosis. Targeting EZH2 may be a potential therapeutic strategy to prevent and treat pulmonary fibrosis post ARDS.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Macrófagos/metabolismo , Fenótipo , Fibrose Pulmonar/metabolismo , Síndrome do Desconforto Respiratório/metabolismo , Animais , Polaridade Celular/efeitos dos fármacos , Polaridade Celular/fisiologia , Técnicas de Cocultura , Lipopolissacarídeos/toxicidade , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/prevenção & controle , RNA Interferente Pequeno/administração & dosagem , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/prevenção & controle
5.
Int Immunopharmacol ; 89(Pt B): 107042, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33068867

RESUMO

Recent studies have shown that epigenetic factors may affect immune responses. We previously reported that histone methyltransferase enhancer of zeste homolog 2 (EZH2) was involved in the innate inflammatory responses both in animal model of sepsis and in septic patients. In this study, we prospectively evaluated EZH2 expression kinetics in peripheral CD4+ and CD8+ T cells and HLA-DR expression in CD14+ cells from 48 patients with sepsis and 48 healthy controls. Results showed higher level of EZH2 in CD4+ T cells and CD8+ T cells in sepsis patients than in controls. Meanwhile, EZH2 expression was correlated with CD27 status on T cells. Mean fluorescence intensity (MFI) of EZH2 in CD8+ T cells on day 1 independently predicted death in septic patients. Also, the combination of CD8+ T cell EZH2 expression with APACHEII and SOFA score could enhance the prognostic predictive ability. Moreover, multivariate logistic regression analysis showed that increased expression (proportion and MFI) of EZH2 in CD4+ and CD8+ lymphocytes on day 3 were independently associated with nosocomial infection in septic patients. Additionally, spearman correlation analysis indicated that the levels of EZH2 in CD4+ T cells and CD8+ T cells correlated to CD14+ cells-expressing HLA-DR in patients with sepsis at each time point. Overall, these findings suggest that EZH2 in CD4+ T cells or/and CD8+ T cells may be a novel biomarker for predicting adverse outcomes (mortality and secondary infectious complications) in patients with sepsis.


Assuntos
Imunidade Adaptativa , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Sepse/metabolismo , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/microbiologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/microbiologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Sepse/imunologia , Sepse/microbiologia , Sepse/mortalidade , Transdução de Sinais , Fatores de Tempo
6.
Int Immunopharmacol ; 76: 105899, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31518916

RESUMO

The function of histone methyltransferase enhancer of zeste homolog 2 (EZH2) in sepsis remains unknown. We reported here that the expression of EZH2 and H3K27me3 was significantly upregulated in the circulation of septic patients, whereas patients who survived presented downregulated the expression of EZH2 on CD14+ monocytes. We further identified increased expression of EZH2 in the circulation, peritoneal fluid, and septic lungs from CLP mice. 3-DZNeP treated CLP mice improved mortality and protected from organ injury. EZH2 inhibition not only suppressed the activation of inflammatory cells and release of cytokines in the circulation and infectious sites, but also promoted bacteria clearance and replenished the circulating monocyte and neutrophil pool from bone marrow. Blockage of EZH2 also suppressed the progression of lung injury and alleviated inflammation by decreasing the pulmonary cell apoptosis, reducing inflammatory cells infiltration and cytokines release through inhibition of the STAT3 signaling pathway and recovery of PPARγ activation. In addition, EZH2 inhibitor blunted macrophage M1 polarization by SOCS3/STAT1 pathway. Overall, these data suggest that EZH2 could be a potential biomarker predicting clinical outcome and a new target for therapeutic interference in sepsis.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Sepse/imunologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Adenosina/uso terapêutico , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Carga Bacteriana , Citocinas/imunologia , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/imunologia , Humanos , Imunidade Inata/efeitos dos fármacos , Histona Desmetilases com o Domínio Jumonji/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/microbiologia , Masculino , Camundongos Endogâmicos C57BL , Fagocitose , Sepse/tratamento farmacológico , Sepse/microbiologia , Sepse/patologia
7.
Biomed Pharmacother ; 111: 733-739, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30611998

RESUMO

INTRODUCTION: The disruption of the balance between antioxidants and oxidants plays a vital role in the pathogenesis of acute lung injury (ALI). Evidence has shown that Lycium barbarum polysaccharide (LBP) has antioxidant feature. We examined the efficacy and mechanisms of LBP on hyperoxia-induced acute lung injury (ALI) in the present study. MATERIALS AND METHODS: C57BL/6 wild-type (WT) mice and nuclear factor erythroid 2-related factor 2 (Nrf2)-deficient (Nrf2-/-) mice were used in the present study. LBP was fed by gavages once daily for 1 week. Then, the mice were exposed to hyperoxia or room air for 72 h. Additional dosage of LBP was given per 24 h. RESULTS: Reactive oxygen species production was increased in WT mice exposed to hyperoxia. Inflammatory cytokines including interleukin (IL)-1ß as well as IL-6, and inflammatory cells were increased infiltration in the lung after 3 days hyperoxia exposure. Hyperoxia exposure also induced pulmonary edema and histopathological changes. These hyperoxia-induced changes were improved in LBP treated group. Moreover, elevated activities of heme oxygenase-1 and glutathione peroxidase and enhanced activation of Nrf2 were observed in mice treated with LBP. However, the benefit of LBP on hyperoxic ALI was abolished in Nrf2-/- mice. Moreover, our cell study showed that the LBP-induced activation of Nrf2 was dampened in pulmonary microvascular endothelial cells when the AMPK signal was inhibited by siRNA. CONCLUSIONS: LBP improves hyperoxic ALI via Nrf2-dependent manner. The LBP-induced activation of Nrf2 is mediated, at least in part, by AMPK pathway.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Medicamentos de Ervas Chinesas/uso terapêutico , Hiperóxia/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/patologia , Animais , Células Cultivadas , Medicamentos de Ervas Chinesas/farmacologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Hiperóxia/tratamento farmacológico , Hiperóxia/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/fisiologia
8.
Neurosci Lett ; 603: 1-5, 2015 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-26189594

RESUMO

The present study explored the time course of response inhibition function in juvenile delinquents with antisocial personality characteristics (JDAP) by recording the event-related potentials in a Go/Nogo task. Compared to healthy participants, JDAP participants showed similar performance to controls for the Go trails, but worse performance for the Nogo trails. Both N2nogo and P3nogo components showed reduction of the amplitudes in JDAP participants, reflecting the early stage of associated with conflict monitoring and the late stage of inhibition processing, respectively. These data suggest that JDAP participants exhibited impaired response inhibition function.


Assuntos
Transtorno da Personalidade Antissocial/psicologia , Potenciais Evocados , Inibição Psicológica , Delinquência Juvenil/psicologia , Adolescente , Humanos , Masculino , Tempo de Reação
9.
J Nanosci Nanotechnol ; 11(11): 9787-90, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22413294

RESUMO

The luminescent complex terbium (III)-trimesic acid (TMA)-1,10-phenanthroline (phen) nanorod was synthesized in the polyvinylpyrrolidone (PVP) matrix by a co-precipitation method. The chemical formula of the synthesized complex was speculated to be PVP/TbL(phen)0.5 x 7H2O by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), elemental analysis and Fourier-transform infrared spectroscopy (FTIR). The X-ray diffraction pattern (XRD) of PVP/TbL(phen)0.5 x 7H2O indicated that it was a crystalline complex. The transmission electron microscopy (TEM) result showed that the complex was nanorods with diameters of about 80-100 nm. The thermogravimetric curve (TGA) analysis exhibited that the complex has good stability below 400 degrees C. UV-Vis diffuse reflectance spectra showed that there is a maximum absorption at 300 nm. The photoluminescence analyses (PLA) showed that the synthesized complex emitted the characteristic green fluorescence of Tb (III) ions under ultraviolet light excitation. The emission peaks of PVP/TbL(phen)0.5 x 7H2O at 488, 542, 581, and 618 nm using 278 nm as exciting wavelength can be assigned to the 5D4 --> 7F6, 5D4 --> 7F5, 5D4 --> 7F4, and 5D4 --> 7F3 electron transitions of the Tb3+ ions, respectively.

10.
J Nanosci Nanotechnol ; 11(11): 9799-802, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22413297

RESUMO

Nano-sized rare earth europium [Eu(III)]-benzoic acid [HL] luminescent complex powders have been synthesized in polyvinylpyrrolidone matrix by precipitation method. The chemical constitution of the complex has been demonstrated as PVP/EuL3 by a combination of elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and fourier-transform infrared spectroscopy (FT-IR). X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) have shown that the complex is a new nanocrystal whose structure is totally different from the ligand. Thermogravimetric/Differential thermal analysis (TG/DTA) have indicated that the luminescent complex is thermally stable below 500 degrees C. Photoluminescence spectra (PL) have shown that the nanocomplex can emit Eu3+ characteristic red fluorescence under ultraviolet excitation.

11.
J Nanosci Nanotechnol ; 10(11): 7494-7, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21137967

RESUMO

Rare-earth luminescent complex have been attracted increasing interest since they can emit fluorescence using near ultraviolet as excitation wavelength. Nanomaterials have potential applications in optical, electronic, magnetic fields due to their surface effects, volume effects, quantum size effects and macroscopic quantum tunnel effects. Combing the important properties of fluorescence and nanomaterial, the study of nanosized rare earth fluorescence complex is an interesting topic. In this paper, we synthesized ternary luminescence complex nanorods composed of europium (Eu (III))-trimesic acid (H3L)-1,10-phenanthroline (phen) using co-precipitation method in the polyvinylpyrrolidone (PVP) matrix. The elemental analyses of the samples were determined using an Inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the chemical composition PVP/EuL(phen)0.2 5H2O was obtained. The X-ray diffraction (XRD) patterns showed that the resulting nano-sized complex is new substance different from that of two ligands. The transmission electron microscopy (TEM) image indicated that the nano-sized complex was nanorod with the average diameter of about 50 nm. Thermal analysis (TGA) result exhibited that the nano-sized complex is stable under 400 degrees C. UV-Vis diffuse reflectance spectra (DRS) showed that there is the maximum absorption at 260 nm. Photoluminescence analysis (PLA) indicated that the nano-sized complex emits Eu (III) characteristic red luminescence under ultraviolet excitation.

12.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 18(3): 629-33, 2010 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-20561416

RESUMO

The purpose of this study was to explore the anti-leukemia effect of quercetin and kaempferol and its mechanism. The HL-60 cells were used as the leukemia models. The inhibitory effects of quercetin and kaempferol on growth of HL-60 cells was assessed by MTT assay. The effect of quercetin and kaempferol on cell cycle in HL-60 cells was detected by flow cytometry. The cytotoxic effect of these 2 drugs was analysed by single cell electrophoresis assay. Western blot analysis was used to study the apoptotic mechanism of HL-60 cells. The results showed that the quercetin and kaempferol had a significant anti-leukemia effect in vitro. The proliferation of HL-60 cells was significantly inhibited in dose-and time-dependent manners after treating with quercetin (r = 0.77) and kaempferol (r = 0.76) respectively, and the cytotoxicity of quercetin was superior to that of kaempferol. The quercetin and kaempferol induced G(2)/M arrest and apoptosis of HL-60 cells. The quercetin and kaempferol could down-regulate the survivin expression. It is concluded that the quercetin and kaempferol have significant anti-leukemia effect in vitro. Furthermore the apoptosis-inducing effect of quercetin is stronger than that of kaempferol, both of which induce apoptosis of HL-60 cells through depressing cell growth, arresting cell cycle and inhibiting expression of survivin.


Assuntos
Apoptose/efeitos dos fármacos , Quempferóis/farmacologia , Quercetina/farmacologia , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Regulação Leucêmica da Expressão Gênica , Células HL-60 , Humanos , Proteínas Inibidoras de Apoptose/metabolismo , Survivina
13.
J Nanosci Nanotechnol ; 10(5): 3060-3, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20358899

RESUMO

The rare earth ion europium(III) was chosen as the central fluorescent ion, and phthalic acid (H2L) was chosen as the ligand. The rod-like phthalic europium(III) fluorescent complex was synthesized using a co-precipitation method in a polyvinylpyrrolidone (PVP) aqueous medium. The chemical composition of the synthesized complex was speculated to be PVP/Eu2L3 x 3H2O by elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and Fourier-transform infrared spectroscopy (FT-IR). The X-ray diffraction analytic (XRD) results indicated that the synthesized complex is a crystalline substance, and the scanning electron microscopy (SEM) analytic results showed that the synthesized complex is nanorod with an average size of about 40 nm. The thermogravimetry and differential thermal analysis (TG-DTA) result showed that the nanoscale complex has good stability below 449 degrees C. Photoluminescence spectra (PL) spectra showed that the nanoscale complex emitted characteristic red luminescence of Eu (III) under ultraviolet light.

14.
J Biotechnol ; 139(2): 156-62, 2009 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19014981

RESUMO

Ricin A-chain can inactivate eukaryotic ribosomes, but exhibits no N-glycosidase activity on intact E. coli ribosomes. In the present research, in order to avoid using radiolabeled oligoribonucleotides, two kinds of synthetic 5'-FAM fluorescence-labeled oligoribonucleotide substrates were used to mimic the sarcin/ricin domains of rat 28S rRNA and E. coli 23S rRNA (32mer and 25mer, named as Rat FAM-SRD and E. coli FAM-SRD, respectively). Ricin A-chain was able to specifically release adenine from the first adenosine of the GAGA tetraloop and exhibited specific N-glycosidase activity under neutral and weak acidic conditions with both substrates. However, under more acidic conditions, ricin A-chain was able to release purines from other sites on eukaryotic substrates, but it retained specific depurination activity on prokaryotic substrates. At pH 5.0, the Michaelis constant (K(m)) for the reaction with Rat FAM-SRD (4.57+/-0.28microM) corresponded to that with E. coli FAM-SRD (4.64+/-0.26microM). However, the maximum velocity (V(max)) for ricin A-chain with Rat FAM-SRD was 0.5+/-0.024microM/min, which is higher than that with E. coli FAM-SRD (0.32+/-0.011microM/min).


Assuntos
Oligorribonucleotídeos/metabolismo , Purinas/metabolismo , RNA Ribossômico 23S/genética , RNA Ribossômico 28S/genética , Ricina/metabolismo , Animais , Escherichia coli/genética , Corantes Fluorescentes/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Conformação de Ácido Nucleico , Oligorribonucleotídeos/química , Oligorribonucleotídeos/genética , RNA Bacteriano/química , RNA Bacteriano/genética , RNA Ribossômico 23S/química , RNA Ribossômico 28S/química , Ratos , Ricina/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...